Requirement of the coiled coil domains of p92c-Fes for nuclear translocation in myeloid cells upon induction of differentiation

The non-receptor tyrosine kinase Fes is expressed in hematopoietic progenitors, differentiated myeloid cells and other cell types, such as vascular endothelial cells and neuroblastoma cell lines. To further clarify this point we performed confocal microscopy and western blot experiments on myeloid cell lines and COS1 cells. In myeloid cells the treatment with differentiation inducing agents such as ATRA, PMA and VD is followed by an increase of Fes abundance in the nuclear compartment. The active form of Fes is phosphorylated on residue 713 and is present into the nucleus while treated cells with the tyrosine kinase inhibitor Genistein clearly showed that phosphorylation is not a required event in order to Fes to translocate to the nucleus.